Amplitude control of a limit cycle in a coupled van der Pol system

In order to control the amplitude of a limit cycle of a coupled van der Pol system, feedback controllers are designed; the control equations of weakly nonlinear systems are obtained by using an approximate method and the relationship between the amplitude of the limit cycle and the control parameter is acquired. Hence the amplitude of the limit cycle can be controlled effectively. The method may also be applied to other coupled van der Pol systems. For some systems, it is difficult to find the function in the amplitude of the limit cycle and the control parameter directly. By means of numerical analysis, we can design effective controllers; therefore we can preferentially control the amplitude of the limit cycle of coupled van der Pol systems.